This invention relates to fittings for connecting electrical cables to a panel and specifically to an improved fitting that provides improved electrical continuity and low millivolt drop between the fitting, the cable, and the junction box.
Historically, the most common form of attaching cable and electrical metal tubing (EMT) to electrical junction boxes was by means of an interior-threaded lock nut, which is screwed onto the exterior-threaded electrical fitting that extends into the junction box.
Recently, snap fitting connectors have become popular as a means of connecting cables to electrical junction boxes. One such type of snap fitting is disclosed in U.S. Pat. No. 5,373,106 (hereinafter the ""106 patent) issued Dec. 13, 1994, and entitled xe2x80x9cSnap In Cable Connectorxe2x80x9d. This patent disclosed a quick connect fitting for an electrical junction box including a spring steel spring member that improved the ease of use and reduced the time involved in securing electrical connectors to electrical junction boxes. This application also disclosed the use of outward-bent tensioner tangs to provide electrical continuity or ground between the electrical connector, the junction box, and the source leading to the box as an integral part of the design of the connector.
An improved snap fitting was disclosed in U.S. patent application Ser. No. 10/053,076 (hereinafter Ser. No. 10/056,076), filed Jan. 17, 2002 and incorporated herein by reference. The snap fitting improved the functionality of the quick connect fitting by providing a spring steel snap ring with a grounding tang of a novel design that provided a tighter fit between the quick connect fitting and the junction box or panel that it connected to. The snap fitting of Ser. No. 10/053,076 therefore improved the electrical continuity and lowered the millivolt drop between the fitting, the cable, and the junction box.
Although the snap fitting of Ser. No. 10/056,076 provided a quick connect fitting with improved continuity, the present invention further improves the continuity of the quick connect fitting by providing a snap ring including a locking tang lanced out of the grounding tang. By lancing the locking tang out of the grounding tang, a greater portion of the outer periphery of the snap ring is available for forming the grounding tang. The larger grounding tangs provide more contact between the junction box and the snap ring thereby providing increased conductivity. The improved snap fitting of the present invention therefore provides improved electrical continuity and a lower millivolt drop between the fitting, the cable, and the junction box.
These and other advantages will become apparent by reading the attached specification and claims in conjunction with reference to the attached drawings.
The present invention comprises a fitting that exhibits improved electrical continuity between the fitting, the cable, and the junction box. The fitting features a hollow electrical connector having an electrically conductive spring member surrounding its leading end. The member includes one or more grounding tangs cantilevered from its outer circumference. Locking tangs are lanced from the grounding tangs. By providing locking tangs integral with the grounding tangs, a greater portion of the periphery of the snap ring is available for forming the grounding tang. The larger grounding tangs provide much greater surface contact area between the grounding tangs and the junction box, thereby improving continuity and lowering the millivolt drop.